Irrlicht Engine

How I can create the effect of vision nocturnal type
splinter cell with irrlicht?

If you mean IR goggles, create separate "thermal" skins.

Downside is, that when you load a BSP file, you probably don't get the option of switching textures at run-time.

This can also be done using shaders, but you'd need to figure out how to load and apply them yourself. That or wait until Niko releases the HLSL Tutorial.

why not make a partly visible night vision texture also

Probably the easiest way (and ugliest) would be to attach a bright green dynamic light to the camera and apply an overlay to the screen (for the lines, interference, etc.)